El Niño–La Niña cycle and recent trends in continental evaporation

Abstract

Climate change is expected to strengthen the hydrological cycle but this is yet to be conclusively shown. Satellite observations are used to investigate changes in terrestrial evaporation, indicating increases at northern latitudes that are in line with expectations. However, global multidecadal variability is dominated by El Niño/Southern Oscillation cycles. The hydrological cycle is expected to intensify in response to global warming1,2,3. Yet, little unequivocal evidence of such an acceleration has been found on a global scale4,5,6. This holds in particular for terrestrial evaporation, the crucial return flow of water from land to atmosphere7. Here we use satellite observations to reveal that continental evaporation has increased in northern latitudes, at rates consistent with expectations derived from temperature trends. However, at the global scale, the dynamics of the El Niño/Southern Oscillation (ENSO) have dominated the multi-decadal variability. During El Niño, limitations in terrestrial moisture supply result in vegetation water stress and reduced evaporation in eastern and central Australia, southern Africa and eastern South America. The opposite situation occurs during La Niña. Our results suggest that recent multi-year declines in global average continental evaporation8,9 reflect transitions to El Niño conditions, and are not the consequence of a persistent reorganization of the terrestrial water cycle. Future changes in continental evaporation will be determined by the response of ENSO to changes in global radiative forcing, which still remains highly uncertain10,11.

Cite this article

Miralles, D., van den Berg, M., Gash, J. et al. El Niño–La Niña cycle and recent trends in continental evaporation. Nature Clim Change 4, 122–126 (2014). https://doi.org/10.1038/nclimate2068

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